Dr. Charlotte Peeters

The environmental niche of Burkholderia multivorans: fitness school for a cystic fibrosis pathogen?

Cystic fibrosis is a genetic disorder with symptoms that are mainly evident in the digestive and respiratory tracts, but lung infections are the main cause of death. Burkholderia cepacia complex (Bcc) bacteria have emerged as significant pathogens in cystic fibrosis patients due to the risk of cepacia syndrome (a fatal necrotizing pneumonia with bacteraemia), the organism's innate multiresistance to antibiotics, and the transmissibility of bacterial strains between patients by social contact. Recent epidemiological surveys either reveal that the proportion of cystic fibrosis patients infected with B. multivorans is rising (like in the UK and USA) or that B. multivorans is the most prevalent Bcc cystic fibrosis pathogen (like in Belgium and France). Studies on the population genetics of B. multivorans revealed evidence for B. multivorans strains having undergone recombination, which may explain the emergence of several more virulent infections.

The concept that environmental pressures can select for traits that confer virulence leads to the possibility that soil or other environments could be regular sources of new pathogens. The continued emergence of unique B. multivorans strains in CF populations suggests acquisition from nonhuman sources, such as the natural environment. Yet, there are so few environmental B. multivorans isolates that its true environmental niche is considered unknown.

The present project aims to determine the environmental niche of B. multivorans, reveal sources of infections and describe its virulence mechanisms.